On Thu, Feb 13, 2025 at 5:13 AM Jiayuan Chen <mrpre@xxxxxxx> wrote:
>
> Add test cases to ensure the maximum stack size can be properly limited to
> 512.
>
> Test result:
> echo "0" > /proc/sys/net/core/bpf_jit_enable
> ./test_progs -t verifier_stack_ptr
> verifier_stack_ptr/PTR_TO_STACK stack size 512 with may_goto with jit:SKIP
> verifier_stack_ptr/PTR_TO_STACK stack size 512 with may_goto without jit:OK
>
> echo "1" > /proc/sys/net/core/bpf_jit_enable
> verifier_stack_ptr/PTR_TO_STACK stack size 512 with may_goto with jit:OK
> verifier_stack_ptr/PTR_TO_STACK stack size 512 with may_goto without jit:SKIP
echo '0|1' is not longer necessary ?
The commit log seems obsolete?
pw-bot: cr
> Signed-off-by: Jiayuan Chen <mrpre@xxxxxxx>
> ---
> .../selftests/bpf/progs/verifier_stack_ptr.c | 50 +++++++++++++++++++
> 1 file changed, 50 insertions(+)
>
> diff --git a/tools/testing/selftests/bpf/progs/verifier_stack_ptr.c b/tools/testing/selftests/bpf/progs/verifier_stack_ptr.c
> index 417c61cd4b19..8ffe5a01d140 100644
> --- a/tools/testing/selftests/bpf/progs/verifier_stack_ptr.c
> +++ b/tools/testing/selftests/bpf/progs/verifier_stack_ptr.c
> @@ -481,4 +481,54 @@ l1_%=: r0 = 42; \
> : __clobber_all);
> }
>
> +SEC("socket")
> +__description("PTR_TO_STACK stack size > 512")
> +__failure __msg("invalid write to stack R1 off=-520 size=8")
> +__naked void stack_check_size_gt_512(void)
> +{
> + asm volatile (
> + "r1 = r10;"
> + "r1 += -520;"
> + "r0 = 42;"
> + "*(u64*)(r1 + 0) = r0;"
> + "exit;"
> + ::: __clobber_all);
> +}
> +
> +#ifdef __BPF_FEATURE_MAY_GOTO
> +SEC("socket")
> +__description("PTR_TO_STACK stack size 512 with may_goto with jit")
> +__use_jit()
> +__success __retval(42)
> +__naked void stack_check_size_512_with_may_goto_jit(void)
> +{
> + asm volatile (
> + "r1 = r10;"
> + "r1 += -512;"
> + "r0 = 42;"
> + "*(u32*)(r1 + 0) = r0;"
> + "may_goto l0_%=;"
> + "r2 = 100;"
> +"l0_%=: exit;"
> + ::: __clobber_all);
> +}
> +
> +SEC("socket")
> +__description("PTR_TO_STACK stack size 512 with may_goto without jit")
> +__use_interp()
> +__failure __msg("stack size 520(extra 8) is too large")
> +__naked void stack_check_size_512_with_may_goto(void)
> +{
> + asm volatile (
> + "r1 = r10;"
> + "r1 += -512;"
> + "r0 = 42;"
> + "*(u32*)(r1 + 0) = r0;"
> + "may_goto l0_%=;"
> + "r2 = 100;"
> +"l0_%=: exit;"
> + ::: __clobber_all);
> +}
> +#endif
> +
> char _license[] SEC("license") = "GPL";
> --
> 2.47.1
>
